COPENHAGEN, Nov 1 (Reuters) - Shares in Pandora (PNDORA.CO), the world"s largest jewellery maker by production capacity, fell sharply on Monday as investors were concerned about weak sales growth at its own stores in the third quarter. The Danish company lifted its full-year outlook, citing strong U.S. sales, but its share price dropped 4.8% in early trade as it also said sales at Pandora stores grew just 5% in the third quarter, while analysts had expected 14% growth.Pandora"s shares had surged 40% this year as the company had seen sales top pre-pandemic levels since shops reopened after lockdowns. "The sell-out growth is kind of disappointing in Q3," said Sydbank analyst Per Fogh. Still, the company said it had continued to see strong sales in the United States, its biggest market, in the third quarter as massive government stimulus and vaccinations against COVID-19 fuelled spending on goods and services. read moreFor 2021, Pandora now expects organic sales growth of 18-20%, up from a previous forecast of 16-18%, and an earnings before interest and tax (EBIT) margin of 24-24.5%, up from a previously forecast 23-24%. However, that was below an average forecast of 24.6% from analysts compiled last monthCOVID-19 and the unusually high level of U.S. growth continue to create increased uncertainty around the guidance," it added. Pandora, best known for its silver charm bracelets, said third-quarter sales came in at 4.73 billion Danish crowns ($734.92 million), beating the 4.67 billion expected by analysts in a poll compiled by the company. It reported quarterly EBIT of 957 million crowns, which was above the 917 million expected by analysts, and resulted in an EBIT margin of 20.2%. "Revenue growth and the EBIT margin were lifted by continued strong U.S. performance and a sequential improvement in Europe as COVID-19 restrictions were eased," Pandora said. The firm will report full third-quarter earnings on Nov. 3.